From long time ago, humans had shown big interests in the night sky that some even worshiped celestial objects such as the moon. The interests later contributed to the development of science. Today, we have artificial satellites that observe the universe. Many people believe that there are other planets like the Earth somewhere, where living things exist. We haven't found any yet, but scientists are still working hard on finding habitable planets, in order to escape from the polluted Earth. From these facts, we can see that celestial objects function as the places to depend on, but it can also make the scientists irresponsible, trying to abandon the Earth.